Steam generator



Nov. 12, 1940. K NER 2,221,382 STEAM GENERATOR Filed Dc. 14, 1937 3 Sheets-Sheget 1 MAX H. KUHNER Nov. 12, 1940. KUHNER 2,221,382

STEAM GENERATOR Filed Dec. 14, 1937 3 Sheets-Sheet 2,.

MA H. K UHNER Nov. 12, 1940.

M.'H.KUHNER. 2221,38;

STEAM GENERATOR Filed Dec. 14, 193'? :5 Sheets-Sheet s J 4.5 Fin 6 MAX H. K UHNER Patented Nov. 12, 1940 FATE ounce f Esteem-GENERATOR Maxi r Killian-Worcester, -Mass.,. assignor' to' Rlileyr Stoker-:Cbrporation; Worcester,r Mass-., aw

corporation oirMassachusetts- I Appliicatibnwnee'ember 14, 193-7; SeriaINo; 179,740

8 claims... (01. me-4am) Ihisinvention relates tosteamgenerators, and

more particularly to steam generatorsof the water tube type.

In my prior United- States Patent" No: 2,oe1;24-1- there is disclosed a steain'generatorcomprising? an upper longitudinal steam-and-water drum connected by a bank 015 upright water'tub'esto a lower longitudinal water drum'therebeneathr In" front of the tube bank there is provided a com bust-ion chamber lined at it's sideswith upright water wall tubes-whichare-connectedat their upper ends to: alongitudinal header in front of" and in alinement' with" theupper 'drum'," this" header being connected-by tubes-to-the' upper" drum. At the rear of the combustion' cha'mber there is a substantial areaofi refractory wallsurface which is exposed to the radiant heat and unprotected by water wall tubes. This isundesirable, as the exposed refractory is comparatively thin and the loss of heat therethrough will be considerable Moreover itis necessary'to" utilize an expensive suspended" arch or some similar construction for the roof of-the combus-tion' chamber beneath the front portion-of the" upper drum.

It is accordingly one object ofthe invention to improve upon. this prior construction and t'o provide means whereby therefractory wall surfaceat the rear of the combustion chambenmay be adequately cooled and supporteda It is. a further object of the:invention'- to-provi'd'e an improved construction f'or the roof of the combustion chamberxat the rearthereof-to elimi-y nate the needfor a suspended archi With these and other objects in View; as will lde'-- apparent to those skilled in thea-rt, the invention resides; in the combinationofparts-set forth in the specification. and covered bythe claims an pended hereto;

Referring! to the drawlngs illustrating one em-- bodiment of the' invention; and in which like" reference numeralstindicate like parts, Fig.1 is a longitudinal-sectiOnethrLiugh a steam generator, the section being taken on the-line 5 of Fig. 2;

Fig; 2 is a sectionon the line '2-i-2 ofFig. 1; Fig. 3 is a section on theline33 of'Fig; 1; Fig. 4 is a sectionionthe line 4-4 of Fig. 1; Fig. 5 isxa top plan view'of the apparatus; i Fig. 6 is a fragmentary'view of amodification,

ShOWIll in. section on the line16--6-of Fig? 7 Fig: 7 is a section onxthe line: 'l-1 of Efg. 63"

Fig. 8 is afragmentary'viewofa further modilfication; shown inlsectiomonzthe lirrei 8i-"-8Jof Fig;-

.9; and: v

The embodiment illustrated in Figs. 1 to 5 in:- clusive comprises "an upper" longitudinal steamand-water drum l0 and a lower longitudinal water drum I I therebeneath,"'the"axesof the twofl drums being located in substantially the same verticalplane. These drums are connectedby'a bank of upright watertubes. I2 with theirend. portions bent to enter the drums radially. Feed water is-"supplied to the rear portion of the upper rearmost rows of tubes 12* to the drum H, andi 0 thenceupwardly through the nextthree rows of tubes-to theupper drum H1 in; front of the baille" l5; The upper drum l-ll is'provid'ed with a steam delivery'no'zzle 18 in its upper wall, and esteem deflect-or plate I Q therebeneatH toremove mois ture from the steam before'itreaches-the'nozzle.

These various parts are mounted inasettingf comprisinga rear wallEB and side walls 21 the latter extending forwardly beyond the" drums l 0 and H to'encl'ose-a combustion chamber or fur- 30? nace Z ZIocatedin front ofthe' tube bank IZ and provided with a front/wall 24 The combustion chamber ispreferably fir-ed through the front wall} and for this purpose there is shown some- Whatdiagrammatically a striker 2523f the well 35 known single retort underfeed type, air-"for com-- bustion being supplied under forced draft through a duct- ZBL The-gaseous-products of combustion travel rearwardly from" the chamber 22 into contact with thetubes IZ and' thence through a 40m dampered gas outlet 28 in the rear wall 20. Transversebafiles 29 are providdamong the tubes 1 2 'to comper the gases: to follow a tortuous path, certainoff these" baffis extendingupwardly" from-the lower drum H and 'others eXtending 45- downwardly from the upper: drum l 0; in an alternate arrangement The front end ofthe lower drum H is' protected by" means of a transverse bridge wall 30"(Fig;* 1) Loose ashes 3| maybe piled ontop of the=bridgewall and against/the 5 adjacent. baffie 29 Adjacent the side walls- 21 of the combustion chamber 22 are rows of upright waten wall "tubes 33 having their lower'en'dsconnected to a pair of horizontaldongitudinal headers -34 located= 011 it extends i row of tubes l2.

the upper portions of the tubes l2.

opposite sides of the combustion chamber. The rear portions of the headers 34 are connected to the lower water drum II by means of tubes 35 (Figs. 1 and 3).

The upper portions of the water wall tubes 33 are bent laterally and extend inwardly above the combustion chamber at a slight upward slope, with the tubes from opposite sides crossing at an elevation somewhat lower than the upper drum' ID, as shown in Fig. 4. The upper ends of the tubes 33 are connected to a pair of horizontal longitudinal headers 31 located adjacent the tops of the combustion chamber side walls 2|. headers are connected to the upper drum II! by means of tubes 38, as shown particularly in Fig. 5.

The sloping upper portions of the water wall,

tubes 33 serve to support refractory material so which forms the roof of the combustion chamber.

The upper headers 3'! are offset with respect to the upper drum 1!], and their rear portions are extended rearwardly beyond the front end of the drum. With this construction the upper laterally sloping portions of the water wall tubes 33 at the rear of the combustion chamber pass beneath the front portion of the drum Ill and make it possible to extend the refractory roof 39 rearwardly as far as the front row of tubes l 2 without requiring a suspended arch. A vertical wall 4%? directly in front of the upper portions of the tubes 12 is likewise supported by the water wall tubes. Furthermore, the side walls 2! are adequately cooled and supported by the water wall tubes not only in the front part of the combus- "and extend inwardly above the combustion chamber at a slight upward slope to the header fl, with which they are connected. The header 41 is offset from the drum [0 and extendsrearwardly beyond the front end of the drum, as shown in Fig.

v6, the side walls of the combustion chamber being supported and protected by the Water wall tubes all the way back to the tubes [2. The inclined portions of the tubes 46 support the combustion chamber roof 39 and the wall 40, at the front of The header 41 is connected to the drum ill by means of the tubes 49.

In Figs. 8 and 9 there is shown a further modified construction in which rows of upright water ;wal1 tubes 50 are provided adjacent the opposite. side walls 2l2l of the combustion chamber 22;

The upper portions of both rows of tubes 50 are bent laterally and extend inwardly above the combustion chamber at a slight upward slope to connect with a single horizontal longitudinal header 5| located above the center of the cornbustion chamber and connected to the drum It) by means of tubes 52. The header 5 l is offset downwardly from the drum I0 and extends rearwardly :therebeneath beyond the front end of the drum.

If desired a tube may be omitted from the center of the front row of tubes l2 to make room for the rear end of this header. The upper sloping portions of the water wall tubes 50 support the combustion chamber roof 39 and the wall 40 at These the front of the upper portions of the tubes 12. Moreover, as shown in Fig. 8, the side walls of the combustion chamber are supported and protected by the water wall tubes all the way back to the tubes l2.

In the operation of the invention fuel is burned in the combustion chamber 22, and large quantities of heat are transmitted by radiation to the water wall tubes. Water flows from the lower drum I [through the tubes 35 to the lower headers 34 and thence upwardly through the water wall tubes to the upper header or headers, as the case may be, and thence to the upper drum I0,

where the steam is released. The hot gases from the combustion chamber flow rearwardly into contact withthe water tubes [2, being directed in a tortuous course by the baffles 29, the gases finally escaping through the outlet 28. The tubes l2 located near the combustion chamber serve as up-comers in which steam is generated, while tubes fartherin the rear serve as down-comers to deliver water from the upper drum to the lower drum. The tubes l2 at the rear of the setting form an economizer in which the feed water is preheated after it has been delivered to the upper drum through the pipe M. The generated steam is withdrawn from the upper drum through the nozzle [8. The roof of the combustion chamber is supported and cooled by the Water wall tubes in a very simple and effective manner, and the front portion of the upper drum is protected from the heat without requiring a suspended arch. The side walls are likewise adequately supported and protected by the water wall tubes even at the rear of the combustion chamber.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: Y

1. A steam generator comprising an upper 1on-;

gitudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upwardly sloping water tubes extending transversely beneath the front portion of the upper drum and in front of the tube bank, means to supply water to the sloping tubes and deliver the steam generated therein to the'upper drum, and a roof for the combustion'chamber supported by the sloping tubes.

2. A steam generator comprising an upper long-itudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upwardly sloping water tubes extending transversely beneath the front portion of the upper drum and in front of the tubebank, a. longitudinal header offset from the upper drum with the rear end of the header extending rearwardly beyond the front end of the drum, the upper ends of the sloping tubes connecting with the header, means connecting the header with the upper drum, and a roof for the combustion chamber supported by the sloping water tubes.

3. A steam generator comprising an upper longitudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upwardly sloping water tubes extending transversely beneath the front portion of the upper drum and in front .of the tube bank, means to supply water to the sloping tubes and deliver the steam generated therein to the upper drum, and an upright transverse wall supported by the sloping tubes and located directly in front of the upper portion of the bank of upright water tubes.

4. A steam generator comprising an upper longitudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upright water wall tubes at one side of the combustion chamber in the rear of the front end of the upper drum, the upper portions of the water wall tubes being bent laterally and extending beneath the front portion of the upper drum and in front of the tube bank, means to supply water to the water wall tubes and deliver the steam generated therein to the upper drum, and a roof for the combustion chamber supported by the upper portions of the water wall tubes.

5. A steam generator comprising an upper 1ongitudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upright water wall tubes at one side of the combustion chamber in the rear of the front end of the upper drum, the upper portions of the water wall tubes being bent laterally and extending beneath the front portion of the upper drum and in front of the tube bank, a longitudinal header ofiset from the upper drum with the rear end of the header extending rearwardly beyond the front end of the drum, the upper ends of the water wall tubes connecting with the header, means connecting the header with the upper drum, and a roof for the combustion chamber supported by the upper portions of the water wall tubes.

6. A steam generator comprising an upper longitudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upright water wall tubes on both sides of the combustion chamber in the rear of the front end of the upper drum, 9. pair of longitudinal headers on opposite sides of the combustion chamber with their rear ends extending rearwardly beyond the front end of the upper drum, the upper portions of the water wall tubes being bent laterally and extending beneath the front portion of the upper drum in a crossed arrangement in front of the tube bank to connect with the headers, means connecting the headers with the upper drum, and a roof for the combustion chamber supported by the upper portions of the water wall tubes.

7. A steam generator comprising an upper longitudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upright water wall tubes on both si es of the combustion chamber in the rear of the front end of the upper drum, a longitudinal header on one side of the combustion chamber with its rear end extending rearwardly beyond the front end of the upper drum, the water wall tubes on the side adjacent the header being connected at their upper ends to the header, and the water wall tubes on the other side having their upper portions bent laterally and extending beneath the front portion of the upper drum and in front of the tube bank to connect with the header, means connecting the header with the upper drum, and a roof for the combustion chamber supported by the said upper portions of the water wall tubes.

8. A steam generator comprising an upper longitudinal steam-and-water drum, a lower longitudinal water drum therebeneath, a bank of upright water tubes connecting said drums, walls forming a combustion chamber in front of the tube bank, upright water wall tubes on both sides of the combustion chamber in the rear of the front end of the upper drum, a longitudinal header above the center of the combustion chamber with its rear end extending rearwardly beneath the front portion of the upper drum, the water wall tubes having their upper portions bent laterally and extending inwardly in, front 

